video tutorial on how to control the shutter/aperture/gain
this is a tutorial i made a few days ago on how to control the aperture and gain on the HV20. i had been up for about 20 hours so you can tell I'm a little muddled and tired. so if someone else want to make a better one that's more clear, please do so
this is the PAL version, so it's basically exactly the same but the NTSC version would have different shutter speeds.
you need a miniSD card in your camera for this to work.
mirror - http://www.megaupload.com/?d=JNDHJMN5
i prefer to use cine mode because you get the extra shutter speeds if you need them. you get 25, 29, 33 ,40 and 50 where as you only get 25 and 50 in TV mode.
Last edited by Patrick Jennings; 2007 May 5th at 09:00.
Great job. I heard all about that, but you explained it really well, and it's very easily duplicated. Many thanks for that.
Any chance we can upoload that video to HV20? Like mentioned here:
EDIT: uploaded now: http://hv20.info/yopu/hv20aperturecontrol.mov
Any idea how STRONG or dim the light has to be that the cam has to be pointed to? I'm gettinmg good results from an LCD screen that is showing a light color (light grey, white). It seems a consistent source of light would be advisable to get duplicable results.
And just to add; it looks like the available shutter speeds in Cine Mode for the NTSC version are: 1/48, 1/40, 1/34, 1/30, 1/24, and then 1/20, 1/17, 1/15, 1/12.
I heard about the possibility of a built-in ND filter; any thoughts on that?
Last edited by Mal; 2007 May 5th at 07:56.
Reason: Patrick's video tutorial uploaded to HV20...
Hi, just joined forum today. I can not correctly view the mov file, my Quicktime says software not available on server, anny suiggestions?
i don't mind if you put it on your server. i just don't want to have to upload it again on my super slow internet connection
a consistent light source would be ideal, but it really doesn't matter how bright or dim it is. you just point it at any light, a lamp, a torch, the sun. it's just trial and error until you get the knack of it.
i think it does have a built-in ND. the smallest aperture the lens can do is f/8 but in TV mode you can close it all the way to f/22.... so i think from 8 to 22 there is an ND of some sort.
The megaupload is down, but I'm looking forward to checking this out.
Okay, it's now on hv20.info:
I think worth a watch for ANYONE with a HV20!
You guys are so for advanced in your camera/camcorder knowledge. I take it this manipulation of the shutter speed & aperature on the HV20 wasn't expected from the typical person purchasing this camera, or it would have been designed to be a little bit more straight forward and easier to do.
Originally Posted by Mal
I finally got in a nice comforatable position last night and dug into the HV20 book. I find the explanations & illustrations on how to do things with this camcorder very hard to follow & I'm a technical person. Is it just me, or are others finding the book to be hard to follow. This is my third Canon camcorder & I believe the others were the same way. I'm a guy and tend to wing it when possible and only go to the book when I can't figure something out. Hope someone brings out a HV20 for Dummies book.
Since I'm obviously from "RioLinda" when it comes to cameras, could you tell me what an ND filter is and also give an example of where you might want to make the effort to manipulate the appeture/shutter settings as illustrated in this video so you could improve your recording. I realize that is a real general question & maybe I'm a bit out of line asking, but could you give an example where point and shoot with this camcorder wouldn't give you very good results unless you went through some of the changes illustrated in this video. I think I know enough to know that you want faster shutter speeds for shooting fast motion and the lower the aperture number the wider the lens is open and thus lets in more light. The aperture also plays a part in the depth of focus or field. There, that reveals how dumb I am. I'm like my computer clients, it's a tool to get a job done. Of course the tool can be a lot of fun but when you don't know how to drive it, it can drive you up the wall.
I like to think that no question is out of line. I've been on boards where peeps will flame newbs hard for stupid stuff but I hope this doesn't happen here.
So the only bad question is the one that you don't ask.
ND is short for Neutral Density. And all that means is it lets in less light. It won't change the color or saturation, just how much. You use ND filters to cut sunshine glare, the blue haze when you shoot landscapes, and when your scene is over exposed. ND filters come in different gradients so you can control how much light you want. If you go to Tiffen's web site, they have all their filters listed and what they do and a very general how and why you'd use them.
As for how and why you'd want to mess with your settings, they teach whole classes on this stuff and it's way out of the scope of anything I'd post in one sitting. My advice would be to search wikipedia for 'aperture', 'shutter speed', 'depth of field', and 'gain'. How they all work together is something most people call, photography 101.
In addition to logging into this forum daily, Mal's best suggestion is to learn by doing. Read the forums and manual (yes Canon has a particular style to its manuals which I think can be pretty challenging), but then go out and shoot with a bunch of different settings so you can see the acutal results. Also - did you know that if you plug your camera into a TV (HDMI or component) in camera mode, you can see all your changes live and immediately compare what one setting looks like vs. another?
Also - on the ND thing, we suspect there is (electronic?) ND filtering already built in to the HV20. Buying additional external ND filters is probably only necessary if you shoot under brightly lit conditions like snow or sand/water, or if for artistic/technical reasons you want the apeture wide open while shooting outside. I used my HV20 recently outside in the midday desert sun and sand in Palm Springs California and the camera had no problem properly exposing the scene without any add-ons.
2010 January 21st, 13:23
Sorry is this has been covered. Adding heavy ND in bright sun would be for using the open aperture to create a shallow DOF look correct?
Originally Posted by 24Peter
Also, if that is true, is an open aperture a negative when trying to shoot fast moving subjects, or does it not matter?
Mal, now I almost got a tear in my eye. I'm thankful that so for all the people here seem to feel the way you feel about it. There appears to be a great diverstiy of people using this forum which makes it really cool. My philosophy has to always keep and open mind and keep on learning. I'll keep on shooting videos and learn as I go. I'm not at all against tweaking and moving out of the "Auto" mode when I can & it will pay royalties. I was just getting a little anxious about the ability to make adjustments as fast as necessary while shooting. Ninety percent of my shooting is outdoors of musicians on a well lit daytime stage or a well lit night time stage plus shooting camp jams in fairly low light. The last one is my big concern. I'll do a lot of testing at home in the evening in the back yard to see what I can come up with as the best camera to use the best way to shoot. Sometimes I'm actually shooting around a campfire and the fire is the only light while other times I might be under a canop;y alongside a trailer and there are a few lights. If the HV20 doesn't hold up well to poor light conditions, I can always move back to my older Canon's - Elura 65 & 100. Actually I have found that a little bit of graininess actually isnt' that bad when your watching a campfire jam. It kind of adds to the ambience. So at times, you can let a technical deficiency become a positvie thing.
Originally Posted by Mal
Say Mal, just one thought I had about the forum. As there become more and more posts that have great solutions in either a step by step or a videos such as Davids, they wind up getting hard to go back an put your finger on them. Do you think where there appears to be a good solution to a problem, they might either be duplicated or moved to a "Solution" thread. I know it would require you objectively determining which ones would warrent being placed into this special thread but I thought you might consder it. They may have to be put into a few categories as the number of solutions get posted. I know from experience with my own website, it gets more and more difficult to organize and implement something like this after the site grows and this forum seems to be growing very rapidly. If it isn't already, this place is going to be the premier website to go to for information about consumer HDV and the Canon DV20 specifically.
I know it's always been a delima in this information age we live in, to quickly put your hands on the information you want. But when you can, it's a wonderful thing.
Last edited by bluegrass; 2007 May 6th at 13:57.
Originally Posted by bluegrass
there's not too much to figure out on the hv20...it is small, very few features, and little to no manual controls. i mean there isn't even a "M" setting, just program mode only. other than shutter/aperture, which have been around since the early 1900s, there isn't really anything new.
just remember this..on the hv20, the higher the shutter, the darker/crisper the image, the lower, the more motion blur and lighter...the higher the aperture the darker, the lower the aperture the lighter.
that's pretty much it for the hv20..you dont have gain controls, or ae shift, or xlr audio inputs, or anything else that is on professional cameras. i mean i love my hv20, but it's like the "AOL" of the HD camera world. dumbed down, stipped, and very little felxibility. there's a reason it's only $1,000..i was really excited when i got it...then after a few hours felt like a cheap plastic toy next to what i've been used to (solid metal, hard rubberized bodies and zoom ring controls, 20x lenses and canon L glass using EF lenses...but the hv20 is good for non-critical filming)
Last edited by crobs808; 2007 May 31st at 16:03.
2007 June 12th, 20:07
Photography basics and the HV20
Hey, all --
This is a fascinating thread; I've been thinking about an HV 20 but had been avoiding it because my understanding had been that it wasn't possible to lock the gain out of function, so Patrick, thanks very much for this.
I don't have an HV20 yet, but do have some background in videography (it's my profession). So, here are some comments inspired by this thread.
Gain: as said before, it's electronic enhancing of a too-dark image. It's measured in dB (decibells) just like audio is measured, because it's a signal strength measurement, not specifically an audio or light level measurement. Perhaps a better analogy of the gain might be in Photoshop (or whatever photo-editing software you prefer) when you use the brightness-contrast control to brighten a photo that's too dark. Sure, you can brighten it, but when you do, all sorts of grain and noise shows in the image.
Shutter (speed): is the amount of time the sensor is exposed to light. It's measured in fractions of a second (or in some cases in full seconds, though I don't know if the HV20 can have multiple-second shutter speeds). The longer the sensor is exposed to light, the brighter the image registers on the sensor. Of course, the longer the sensor is exposed to the light, the more opportunity you have for motion-blur -- that is your subject can move while the shutter is open. If you're shooting at 30 frames per second (which is more or less equivalent to 60i), you can shoot as slowly as a thirtieth of a second per frame and still have normal looking motion. If you're shooting at 24 frames per second, the camera can keep its shutter open for a 24th of a second, or nearly 30% longer, and therefore can capture images in slightly lower light conditions. If the camera can shoot at, say, 1/12 of a second, it will keep the shutter open for 1/12 of a second and send the same image to two frames (at 24fps). This will result in somewhat choppy motion, but will allow you to shoot in half as much light. Depending on the subject, it might work.
Aperture: This is the diameter of the opening through which the light travels to the image sensor. Aperture is measured in f-stops. (F-stops are calculated as the ratio of the size of the opening to the focal length of the lens; interesting but not entirely necessary to know.) The important thing to know is that the smaller the f-stop number, the larger the opening. And the larger the opening, the more light can pass through the lens to the image sensor. A physical property of lenses is that the smaller the opening (higher the f-stop number) the greater the "depth of field" of an image -- that is, the longer range of distance that objects will be in focus.
So, if you have a tape measure on the floor running lengthwise away from you and you point a camera at it, you'll see that a particular distance is in focus. Let's say that you're shooting at f-5.6 at a shutter speed of 1/60 of a second. You look at the image and see that the 3 foot mark is crystal clear, but the 2'10" mark is a little "soft" and the 3'4" mark is a little soft. If you open up the aperture (say to f-4), you'll be letting more light in, so to keep the exposure the same, you'll need to change the shutter speed to 1/120 of a second. Because the aperture (f-stop) is larger now (smaller number), the depth of field is "shallower", so all that will be in focus is from 2'11" to 3'1". But let's say you want more of the tape measure in focus. So, you change the aperture to f-8. To keep the exposure the same, you'll need to change the shutter speed to 1/30 of a second. But at f-8, you will see that the focus will be clear from 2'8 to 3'8.
This is why it's important to have control of aperture and shutter speed. Patrick's tutorial shows how to take complete control of the exposure in your camera, which is really important if you want that much control of the image.
But for most hobby applications (and a number of professional ones), the automatic settings are just fine. They'll help you get a clear, properly exposed image to the best of the camera's ability. So, for your child's first steps, by all means, use the automatic. Under most circumstances, it'll look great!
That's probably a LOT more info than anyone was asking for, but hey, I used to teach TV production, so it's hard for me to resist!
I'll keep reading this forum and very likely will be buying an HV20 soon.
Thanks for all the great info here!
2007 June 12th, 20:46
2008 March 12th, 22:03
Not only hard to understand the manual... it is set the smallest type and on tissue paper that makes it even harder to read.
Canon should also hire some people who can proof read their manual and express it in a better term.
However, at least the hardware is nice
2008 March 13th, 07:53
i like the trick.
forces me to control the scene (lighting), not the scene controlling the camera.
use it all the time.
2008 March 27th, 17:11
Dont know if i this right
i tried this for 2 hours and heres what i got
-11 (EXPOSURE) = f4.8 ( 1/60 NTSC )
-10 = f4.4
-9 = f4.0
-8 = f3.7
-6 = f3.2
-5 = f2.8
-4 = f2.6
-3 = f2.4
-2 = f2.2
-1 = f2.0
+0 = f1.8
+1 = f1.8
+2 = f1.8
+3 = f1.8
+4 = f1.8
+5 = f1.8
+6 = f1.8
...And so on until +11 (BTW +11 = f1.8 )
2008 March 27th, 17:22
Formerly Known As "Aramis"
This is 4 minutes 27 seconds per EV step. Bravo!
Originally Posted by milespapineau
2008 March 19th, 01:40
2009 April 24th, 21:21
Can't get my arms aroudn this
I bought this camera to avoid any potential equipment conflicts regarding my YouTube activities, and am having difficulty getting my arms around this "auto gain" issue, being used to gear that allows me to switch it on and off.
Originally Posted by David
Am I right to assume that if I were to use the Tv mode to lock the shutter and then make sure I had sufficient light to kept the f-stop above it's minimum setting, there would be no reason for the camera to goose the gain and I could therefore be sure of clean video? Or am i missing something.
Great tutorial! I got a question answered that I was thinking about for a while.
Thanks a million!
YAY I got sticky status! I'm glad you all found it helpful